SANTA CLARA -- As the 49ers bid farewell to safety Donte Whitner, they've apparently found his replacement in Antoine Bethea, who's played all his previous eight seasons with the Indianapolis Colts.

"Glad to be a Niner!! Going to the Bay!!!" Bethea posted on Twitter.

Bethea, 29, totaled 14 interceptions in 123 career starts for the Colts. Like Whitner, he is a product of the 2006 draft, although he was a sixth-round pick out of Howard whereas Whitner went No. 6 overall out of Ohio State (to the Buffalo Bills).

ESPN's Adam Schefter first reported that Bethea had agreed to a deal with the 49ers, sharing that news some 10 minutes after free agency began Tuesday. Bethea's agent, Adisa Bakari, declined comment when reached by phone. The Sacramento Bee reported that Bethea agreed on a four-year deal.

The 49ers did not immediately announce anything regarding Bethea -- or Phil Dawson's re-signing -- but they did state that cornerback Carlos Rogers has been released, as anticipated Monday.

Unlike Whitner, Bethea rarely has drawn penalties, and he wasn't called for any last season. Bethea has been penalized 13 times in eight seasons, and only three of those infractions were for unnecessary roughnes. Whitner got flagged a team-high five unnecessary-roughness last season, including in the NFC Championship game loss to the Seahawks.

Whitner reportedly signed a four-year, $28 million deal with his hometown Browns, according to ESPN and NFL Media reports.